Screw-machine.



J. C. POTTER.

SCREW MACHINE.

' APPLICATION FILED SEPT. I4, 1909.

Patented Apr. 20, 1915.

THE NORRIS PETERS CO. PHOTOYLITHOH WASHING TONv D C 3O chine Co, issuedMarch 23, 1909, which in- @NTTED STATE PATENT @FFTCE.

JAMES C. POTTER, OF PAWTUGKET, HI-IODE ISLAND.

SCREVJ -1VIACHINE.

To all whom it may concern: 1

Be it known that T, JAMES 0. Forms, of Pawtucket, in the county ofProvidence, and in the State of Rhode Island, have invented a certainnew and useful Improvement in Screw-l\ lachines, and do hereby declarethat the following is a full, clear, and exact description thereof.

The object of my invention is to enable the use of solid taps and diesin automatic screw machines, and to this end my invention consists inthe screw machine con structed substantially as hereinafter specifiedand claimed.

Referring to the drawings, the figure shows a longitudinal section of anautomatic screw machine embodying my invention.

The machine illustrated in the drawings as embodying my inventioncomprises a head stock 10, having a chuck-carrying spindle 11, a slide12 carrying a tool turret 13, the slide being reciprooable toward andfrom the chuck by a cam drum 14:, in a manner well understood in thisart.

Loose upon the head stock spindle are two spur gears 15 and 16,respectively, which may be alternately clutched to the spindle as bymeans of a friction clutch 17, such, for example, as that which formsthe subject of patent of Potter & Johnston Macludes a sliding collar 18splined to the shaft, and having an operating lever 19. The spur gears15 and 16, revolve in opposite directions so that one rotates thespindle in one direction and the other in the opposite direction, thegear 15 being in mesh with a pinion 20 on a shaft 21 extending parallelwith the spindle, and the gear 16 being in mesh with an intermediate oridler pinion 22 that meshes with a pinion 23 also on said shaft 21. Theshaft 21 has upon it a gear 2% which through a suitable train of gears,including a shaft 25 with severalas shown, threegears 26 adapted one ata time to be clutched to the shaft 25, receives power from a main shaft27 and thereby imparts a variable speed to the spindle. The main shaft27 has a band Wheel 28 which is belted to a counter shaft. The speed ofrevolution of the turret slide moving drum is also vari-? able, and inorder to have the change of;

speed of spindle and tool take place in right relation, the turrentslide moving cam drum and the spindle are geared or connected to-'Specification of Letters Patent.

Application filed September 14, 1909.

Patented Apr. 20, 1915.

Serial No. 517,696.

gether, this being accomplished in the case of the machine shown in thedrawings, by providing the shaft 21 with a band wheel or pulley 29 thatis connected by a belt with a pulley or band wheel 30 and journaledconcentric with and to turn independent of the main shaft, and whichthrough suitable gearing, not necessary to be described, transmits powerto the turret actuating cam drum. In cutting thread, whether by means ofa tap or die, the spindle is revolved in one direction during a threadcuttin operation, and in the opposite direction or the retraction fromthe work of the thread cutting tap or die, and the rate or speed ofrevolution of the spindle should be in proper proportion to the rate ofrearward travel of the turret slide, so that disconnection of the threadcutting tool and the work may take place without injury to the work, andenabling the employment of a solid tap or die for cutting the thread.

In order to render the reversal of revolution of the spindle automatic,and to cause it to take place upon the completion of the threadingoperation, I pivot to the clutch operating lever 19 one end of a rod orbar 31, whose other end is in the path of one or more cam lugs 82clamped to a wheel 33 on a shaft 34: that through suitable connectionreceives motion from the main driving shaft. Certain of the cam lugs actto move the clutch operating lever in one direction, and others in theopposite direction, so that the time and direction of revolution of thespindle are automatically controlled.

It will be seen that by the employment of the shaft 21, I am able toobtain the im portant advantage of gearing together the head stockspindle and the turret slide, so as to secure the changes of speed ofspindle and tools in the proper relation, because said shaft 21 suppliespower to the spindle and to the turret slide cam drum, and also am ableto reverse the direction of revolution of the spindle. Were there adirect connection between the head stock spindle and the turret slidecam drum revolving mechanism, and were there a direct connection betweenthe gears and the spindle for revolving the the latter at differentspeeds, the reversal of the revolution of the spindle would beimpossible, since it would involve a reversal of all the mechanism whichwould thus be directly connected with the spindle.

Having thus described my invention, What I claim is- The combination ofa Work spindle, a'tool carrier reciprocable toward and from the Work, avariable speed shaft separate from the spindle, tWo driving connectionsbetween said shaft and said spindle, that respectively revolve the samein opposite directions including clutch devices mounted on the spindle,means acting on said clutch devices to render said driving connectionseffective at different times, tool carrier moving means, and gearlngbetween sald varlable speed 7 Copies of this patent may be obtained forfive cents each, by addressing the Commissioner of Patents,

versed, said gearing receiving its motion independently of the spindle.V

In testimony that I claim the foregoing I have hereunto set my hand.

JAMES C. POTTER.

Witnesses:

r W. WALLACE lPo'r'rnR,

ELVERY LINGARD.

Washington, D. G.

